backlight device, suspend/resume...

Carsten Haitzler (The Rasterman) raster at
Wed Jul 9 16:49:54 CEST 2008

On Wed, 9 Jul 2008 11:32:11 -0300 Werner Almesberger <werner at>

> Carsten Haitzler wrote:
> > it can be extended to understand more devices (gps, wifi, etc.) with the
> > current dbus api. so it sits in a middle land - a system level daemon that
> > also understand a little bit of the raw basics of the gui.
> Perfect, that's precisely what we need. Thanks !
> > we've spent more text talking about this than the daemon source code
> > size... :)
> Yeah, but it is also important that we all understand what's happening :)

sure. :) i have given this some thought and research and i am fairly sure that
nuts-and-bolts wise this is a good way to go. as  i said - it has holes - ie
apps crashing and leaving locks on a device. for now i'm going to assume that
the very few apps that do this are able to restart (themselves or via another
mechanism) and clean up after themselves. kill ompower and restart it and
things are reset if any clients go "strange" and leave hanging locks. for the
moment given we are only going to have very few clients it's managable, and i
will address this in the future, but i need a solution NOW for ASU that can be
improved in future.

i can happily add lots of dbus calls that would allow for other clients to do
the cleaning up if things ever get into an undesirable state if there are bugs.
so to fine-tune and remove "locks" if left around one at a time, but as above,
for now, no need, just get the basics up and working, the very few apps (really
for now only 2) to work correctly and that's it. move on :)

> In fact, the only think I dislike about your daemon is that it came as
> such a surprise ;-)

that's cool. it wasn't meant to be. it's me just knuckling down and
addressing an issue that we have had floating about for a while without any
fanfare. :) all i'd like is for resume to restore the backlight as it was left
and i can make it function really well. it already works - but it is hacked to
assume backlight is on on resume and that there is no choice in that. this is
ok - until you think of all the cases where u want resume without a backlight :)

Carsten Haitzler (The Rasterman) <raster at>

More information about the openmoko-kernel mailing list